<!DOCTYPE html>
<html>
<head>
	<meta charset="UTF-8">
	<title>三行自适应布局</title>
	<style>
		.head{position: absolute;top: 0;left: 0;width: 100%;height: 100px;background-color: #ccc;}
		.body{position: absolute;top: 100px;left: 0;bottom: 100px;right: 0;overflow: auto;}
		.content{height: 2000px;}
		.foot{position: absolute;bottom: 0;left: 0;width: 100%;height: 100px;background-color: #ccc;}
	</style>
</head>
<body>
	<div class="head">head</div>
	<div class="body">
	  <div class="content">content area</div>
	</div>
	<div class="foot">foot</div>
</body>
</html>